Air Velocity Transmitters

Cable Length	Output Signal	Operating Temp.	Response Time	Temp. Limit (deg. F)	Range	Output	Resolution	Price
72"	4-20 mA	-40°F to +212°F	1.5 sec.	+32°F to +140°F	250 FPM	4-20 mA	1 FPM	SGD 1,354.35
6"	4-20 mA	-40°F to +212°F	1.5 sec.	+32°F to +140°F	250 FPM	4-20 mA	1 FPM	SGD 1,704.11

DWYER INSTRUMENTS

641 Series Air Velocity Transmitters

Probe Length	Output Signal	Operating Temp.	Response Time	Display	Temp. Limit (deg. F)	Electrical Connection	Connection Size	Price
6"	4-20 mA	-40°F to +212°F	1.5 sec.	-	+32°F to +140°F	Screw Terminals	1/2"	SGD 1,320.76
12"	4-20 mA	-40°F to +212°F	1.5 sec.	-	+32°F to +140°F	Screw Terminals	1/2"	SGD 1,328.23
6"	4-20 mA	-40°F to +212°F	1.5 sec.	LED	+32°F to +140°F	Screw Terminals	1/2"	SGD 1,655.51
12"	4-20 mA	-40°F to +212°F	1.5 sec.	LED	+32°F to +140°F	Screw Terminals	1/2"	SGD 1,605.40
18"	4-20 mA	-40°F to +212°F	1.5 sec.	LED	+32°F to +140°F	Screw Terminals	1/2"	SGD 1,775.81
18"	4-20 mA	-40°F to +212°F	1.5 sec.	-	+32°F to +140°F	Screw Terminals	1/2"	SGD 1,354.35
24"	4-20 mA	-40°F to +212°F	1.5 sec.	-	+32°F to +140°F	Screw Terminals	1/2"	SGD 1,342.28
24"	4-20 mA	-40°F to +212°F	1.5 sec.	LED	+32°F to +140°F	Screw Terminals	1/2"	SGD 1,665.82

DWYER INSTRUMENTS

AVUL Series Air Velocity Transmitters

Accuracy	Communication Method	Response Time	Output Signal	Probe Length	Temp. Limit (deg. F)	Electrical Connection	Connection Size	Price
-3% to +3%	Analog + BACnet MS/TP	10 sec.	4-20 mA	7 41/64"	+32°F to +122°F	Analog	1/2"	SGD 965.87
-5% to +5%	Analog + BACnet MS/TP	10 sec.	4-20 mA	7 41/64"	+32°F to +122°F	Analog	1/2"	SGD 686.23
-3% to +3%	Analog Universal	10 sec.	-	7 41/64"	+32°F to +122°F	Analog	1/2"	SGD 772.52
-5% to +5%	Analog + Modbus RTU/ASCII	5 sec.	4-20 mA	7 41/64"	+32°F to +122°F	Analog	1/2"	SGD 686.23
-5% to +5%	Analog Universal	10 sec.	4-20 mA	7 41/64"	+32°F to +122°F	Analog	1/2"	SGD 430.12
-3% to +3%	Analog Universal	5 sec.	4-20 mA	7 41/64"	+32°F to +122°F	Analog	1/2"	SGD 668.07
-3% to +3%	Analog + Modbus RTU/ASCII	10 sec.	4-20 mA	7 41/64"	+32°F to +122°F	Analog	1/2"	SGD 924.76
-3% to +3%	Analog + BACnet MS/TP	5 sec.	4-20 mA	7 41/64"	+32°F to +122°F	Analog	1/2"	SGD 942.44
-5% to +5%	Analog Universal	5 sec.	4-20 mA	7 41/64"	+32°F to +122°F	Analog	1/2"	SGD 541.16
-5% to +5%	Analog + BACnet MS/TP	10 sec.	4-20 mA, 0-5V DC, 0-10V DC	7 41/64"	+32°F to +122°F	Analog	1/2"	SGD 789.05
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Description

Dwyer Instruments air velocity transmitters are designed to monitor the airflow in exhaust stack flow and ventilation tracking operations, as well as in HVAC or cleanroom systems. These CE marked transmitters feature a heated mass flow sensor to provide precise velocity measurements at flow rates ranging between 0 and 15000 fpm and a push-button set-up facility for hassle-free calibration. Selected models come equipped with a digital filter to dampen the signals and a NEMA 4X rated enclosure for installation in confined spaces. These transmitters are capable of being operated at temperatures ranging from -40 to 212 degrees F. These Dwyer air velocity transmitters are available in 6, 12, 18 and 24 inch probe length options on Raptor Supplies.

Working Mechanism

Air velocity transmitters use sensors to detect airspeed.
These sensors measure the force of the air pushing against them.
The force detected by the sensor increases as the air moves more quickly.
This information is then converted into an electrical signal, usually in the form of voltage or current.
By monitoring this signal, users can determine the velocity of the air in real time.

Features

These CE-marked transmitters feature a heated mass flow sensor to provide precise velocity measurements at flow rates ranging between 0 and 15000 FPM and a push-button set-up facility for hassle-free calibration.
They are capable of being operated at temperatures ranging from -40 to 212 degrees F.
Selected models come equipped with a digital filter to dampen the signals and a NEMA 4X-rated enclosure for installation in confined spaces.
Dwyer Instruments 641 Series air velocity transmitters feature digital filter for eliminating noise, fluctuations and unwanted artefacts from the raw sensor signal, resulting in a cleaner and more reliable output. Selected models feature a bright led display for getting readings in low-light conditions. NON-LED variants have NEMA4X enclosures for preventing contaminants. These air velocity transmitters can be operated at pressures up to 100 psi.
Dwyer 641RM Series air velocity transmitters with remote probes feature a compact design for installation in tight spaces. They are equipped with function buttons for easy setting up of them. These air velocity transmitters have screw terminals for easy connection and strong conductivity. They have a measuring range of 250 FPM to 15000 FPM. These air velocity transmitters have ambient operating temperatures ranging from 32 to 140 degrees F.

Frequently Asked Questions

How to maintain air velocity transmitters?

Regularly clean the air velocity transmitter and sensor to remove dust and debris.
Calibrate the transmitter periodically to ensure accurate measurements.
Inspect and replace any damaged or worn-out components.
Ensure proper power supply and electrical connections.
Protect the transmitter from extreme temperatures and environmental conditions.

How does a digital filter in an air velocity transmitter smooth out fluctuations in the measured velocity?

Digital filter can smooth out fluctuations in the measured velocity by attenuating rapid changes or variations in the sensor signal. By adjusting the filter parameters, such as the cut-off frequency or time constant, the filter can provide a controlled response to changes in the velocity signal. This smoothing effect helps to eliminate high-frequency noise or short-term fluctuations, resulting in a more stable and consistent velocity measurement over time.

Why is noise reduction important in an air velocity transmitter?

Noise reduction is crucial in an air velocity transmitter because it helps improve the accuracy of the measured velocity data. Air velocity measurements can be affected by various sources of noise, such as electrical interference or random fluctuations in the sensor signal. By applying digital filters to reduce noise, the transmitter can provide a cleaner and more reliable output, enabling better decision-making and control in applications that rely on accurate velocity information.

Does Dwyer offer air velocity transmitters that allow adjustable transmitting range?

Yes, Dwyer 641 Series air velocity transmitters allow users the flexibility of choosing from 8 different ranges, ranging from 250 feet per minute (FPM) to 15000 FPM, with corresponding metric range of 1.25 meters per second (MPS) to 75 MPS.

How to detect air velocity in hard-to-reach areas?

You can use Dwyer air velocity transmitters. They have six-foot-long cables that assist users in detecting air velocities in confined spaces or hard-to-reach areas.

What factors can affect the accuracy of air velocity transmitters and how can users ensure accurate readings?

Regular calibration according to manufacturer guidelines is crucial for maintaining accuracy.
Sensor positioning within the airflow path is critical. Improper placement, such as near bends or obstructions, can result in turbulence and inaccurate readings.
Temperature, humidity and barometric pressure variations can affect air density, impacting measurement accuracy. Ensure the transmitter is calibrated for these conditions.
Different sensor types have varying accuracies and response times. Choose a sensor type that suits the specific application and accuracy requirements.
Consider the flow profile and select the appropriate number and placement of sensors.